The present invention relates to a magnetic tape cutting system that cuts off the magnetic tape from a magnetic tape roll, takes up a normal portion of the magnetic tape as a product, and removes the defective portion of the magnetic tape.
In the magnetic tape, when magnetic material is applied to a support body for forming the magnetic tape, in some cases, a dust sticks to the magnetic material thereby such as an uneven of the magnetic material is given, which causes a defect in the magnetic tape. Therefore, in a stage of forming the roll, the magnetic tape is checked as to whether a defect is present or not.
In a case of a magnetic tape which is used as a data backup, a servo signal is previously recorded in the magnetic tape. In such magnetic tape, the wrong writing of the servo signal can also give a defect, and therefore, the magnetic tape is checked for the presence or absence of a defect caused by a servo signal recorded therein.
As a magnetic tape cutting system of the above type, there is known an apparatus disclosed in JP-A-7-37362. In this magnetic tape cutting system, from a roll with a defect position of a magnetic tape previously recognized by inspection, a magnetic tape with a predetermined length for a product is cut off and is then taken up around a reel disposed within a cassette.
According to this apparatus, the defect position is recognized and stored by a storage unit. In case where no defect is present in the magnetic tape with the predetermined length to be cut off, the magnetic tape with the predetermined length is taken up around a reel (specifically, a product reel) disposed within the cassette. On the other hand, in case where a defect is present in the magnetic tape with the predetermined length to be cut off, the magnetic tape with the predetermined length is taken up around a disposal reel so that the magnetic tape having the defect can be disposed. Take-up of the magnetic tape on the product reel and take-up of the magnetic tape on the disposal reel are carried out within the same winding apparatus (winder).
In the interior of the above winding apparatus, there are provided a mechanism for taking up a magnetic tape on a product reel, a mechanism for taking up a magnetic tape on a disposal reel, and a mechanism for guiding a magnetic tape played out from a roll to either the product reel or the disposal reel. However, this winding apparatus has very complicated internal structure, requires high costs for installation thereof, and is troublesome in the maintenance thereof. Also, during the time while the magnetic tape is being taken up on the disposal reel, the production of the magnetic tape is stopped, which provides an obstacle to a productivity increase.
It is an object of the present invention to provide a magnetic tape cutting system for eliminating the above drawbacks found in above the magnetic tape cutting system. Accordingly, it is an object of the present invention to provide a magnetic tape cutting system which can reduce its cost and is easy to handle.
In attaining the above object, according to the present invention, there is provided a magnetic tape cutting system, comprising: a storage unit for storing positional information of defect portions of a whole roll of magnetic tape; a winding apparatus for playing out a magnetic tape from the whole roll and winding the magnetic tape as a product; a defect removal apparatus for playing out a magnetic tape from the whole roll for disposal; and, a control unit, based on the positional information of the defect portions, selecting one of the winding apparatus and the defect removal apparatus in which the magnetic tape is played out from the whole roll.
Also, in attaining the above object, according to another aspect of the present invention, there is provided a magnetic tape cutting method, comprising the steps of storing positional information of defect portions of a whole roll of magnetic tape in a storage unit; taking up normal portions of a magnetic tape from the whole roll as a product, based on the positional information of the defect portions, by a winding apparatus; and removing the defect portions of the magnetic tape from the whole roll by a defect removal apparatus.
According to the above structure, the control means, based on the positional information of the defect portion stored in the storage unit, selects as to whether the whole roll of magnetic tape is loaded into the winding apparatus or the defect removal apparatus. Then, the magnetic tape is then played out from the whole roll. The defect removal apparatus is separately disposed from the winding apparatus. Since the winding apparatus according to the present invention may have neither a function to take up the magnetic tape on the disposal reel nor a function to guide the magnetic tape played out from the whole roll to either of the product reel or disposal reel, the winding apparatus is simple in structure. Also, the structure of the defect removal apparatus can also be simplified. Therefore, the installation cost of the magnetic tape cutting system can be reduced. Also, the magnetic tape cutting system is easy in maintenance and is also easy to handle.
It may seem that separate disposal of the defect removal apparatus and winding apparatus can lower the yield rate. However, thanks to the recent progress in the communication technology, information sharing among a plurality of apparatus can be realized easily. The inventors have paid special attention to this and have found out the following fact. That is, in case where a defect removal apparatus separately disposed from the winding apparatus is used and information is properly shared between them, the productivity can be maintained or enhanced.
On the other hand, in case where the defect removal apparatus and the winding apparatus are disposed within the same apparatus, the production is stopped during the execution of the defect removal, which lowers the productivity.
However, according to the present invention, for example, with reference to the positional information of the defect portion stored in the storage unit, a predetermined length of magnetic tape is played out from the whole roll and is then taken up as a product by the winding apparatus. Then, the play-out of the magnetic tape is stopped at the vicinity of the defect portion and the magnetic tape is cut off from the product. Next the cut-off roll is moved to the defect removal apparatus, and the defect portion of the magnetic tape can be removed by the defect removal apparatus. After the defect portion is removed from the roll by the defect removal apparatus, this roll can be moved again to the winding apparatus. In this case, there is no restriction that the winding apparatus must be one used in the previous time, that is, the roll can be used to any of winding apparatuses.
The movement of the whole cloth between the winding apparatus and defect removal apparatus can be transferred by transfer means (automatic means) such as a robot; however, this is not limitative but the movement of the roll may also be transferred by hand.